Query on short term capital gain on equity specific scenario

Thanks for the reply.

Amount mentioned here is to just simplifying the case. The only doubt I have here is that, though stock prize is appreciated here 100%, I have sold only 50% of my stock holding so I have just got my initial capital 100 Rs back. So unless I start selling my remaining 5 stocks, I am not actually earning any profit. Then in this case how can it attract the tax?